Professor Andrew Turberfield

Abstract:

A range of techniques employed for 3D optical lithography including atomic layer deposition (ALD) and holographic lithography has been demonstrated. A 3D photonic crystal structure can be written by holographic lithography which makes use of a periodic interference pattern generated by a multiple-beam interferometer to expose a thick layer of photoresist. 3D microstructures can also be generated by point-to-point exposure of the resist by two-photon absorption at a laser focus. The potential of ALD has been explored to develop a well-controlled infiltration technique for optically fabricated 3D microstructures used for the formation of single- and multicomponent inverse opals. A high quality photonic crystal in amorphous TiO2 was produced by conformal infiltration followed by etching of holographically defined polymeric templates. The results show that the combination of holographic lithography and ALD allows rapid and flexible fabrication of 3D photonic crystals.